2 William Mobton Wheeler. 



from the insects, but when this is done, only a black, crumbling, residue 

 of decomposed chitin remains. At least this was all I saw of the few 

 common specimens which I attempted to free from their matrix. 

 KoRNiLOWiTSCH ^) in a paper cited by Klebs, seems to have shown that 

 even the fine histological details of the leg musculature may be 

 preserved in Diptera and Neuroptera, but I have never observed such 

 details in the ants in situ, although the chitin of their legs is often 

 very transparent. 



All the little blocks of amber containing the specimens belong- 

 ing to the various collections had been carefully cut and polished, 

 and, in many instances, enclosed in cells full of Canada balsam and 

 mounted on slides, to preserve them from the slow darkening in color 

 and partial opacity, which the originally very transparent, pale yellow 

 amber is liable to take on when long exposed to the air. This change 

 is, unfortunately, very noticeable in Mayr's types, which were simply 

 glued to slides and are now much darker and more obscure than they 

 could have been when the distinguished myrmecologist described them 

 nearly half a century ago. All the specimens in the Klebs, Brussels, 

 Berlin and Haren Collections and most of those in the Konigsberg 

 Collection are carefully numbered. Except in cases where there are 

 very many specimens of the same species, I have taken pains to cite 

 all these numbers, so that my types and often also a long series of 

 cotypes may be readily recognized by any future investigator, 



Mayr's work on the ants of the Baltic amber published in 1868^) 

 is such a thorough and comprehensive masterpiece that even the much 

 larger amount of material which has since accumulated, necessitates 

 comparatively few changes. That this work has enormously facilitated 

 my study, goes without saying. As his species are all easily re- 

 cognizable from his descriptions and figures, notwithstanding the 

 somewhat diagrammatic character of the latter, I have deemed it unne- 

 cessary to repeat his tables or to rewrite the majority of his diagnoses 

 and the history of the older literature of the subject. Since 1868 

 very little attention has been devoted to the amber ants, Emery 3) and 

 Ern. Andre 4j have described a few species, and the former has mono- 



1) Hat sich die Struktur der quergestreiften Muskeln im fossilen Bernstein er- 

 halten? Sitzb. Naturf. Gesell. Dorpat, XIII, 1903, pp. 198—203. 



2) Die Ameisen des baltischen Bernsteins. Beitrage zur Naturkunde PreufBens, heraus- 

 gegeben v. d. physik.-okonomischen Gesellschaft zu Konigsberg, I, 1868, 102 pp. 5 pis. 



3) Deux Fourmis de I'Ambre de la Baltique. Bull. Soc. Ent. France, 1905, 

 pp. 187— 189, 2 Figs. 



*) Notice sur les fourmis fossiles de I'ambre de la Baltique et description de deux 

 espfeces nouvelles. Bull. Soc. Zool. France XX, 1895, pp. 80—84. 



